950G Wheel Loader, 962G Wheel Loader and IT62G Integrated Toolcarrier Power Train Caterpillar

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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. Prevent possible injury by performing the procedure that follows before working on the machine.

1. Park the machine on a smooth, level surface.

2. Place the transmission direction and speed control lever (if equipped) in the NEUTRAL position and in any speed position. Shift the transmission direction control switch (if equipped) to the NEUTRAL position.

3. Lower the bucket and/or the attachment to ground.

4. Engage the parking brake.

5. Place blocks in front of the wheels and behind the wheels.

6. Install the steering frame lock.

7. Remove the front axle shafts and rear axle shafts except for stall tests.

8. Allow only authorized personnel on the machine. Keep unauthorized personnel off the machine and in clear sight of the operator.

Note: All tests and all adjustments must be made while the transmission oil is at normal operating temperature.

Test Procedures

Transmission Clutch Solenoid Modulating Valves Test

This test will determine whether the solenoid coil is energized and the solenoid plunger is shifting in order to permit the flow of oil through the transmission clutch solenoid modulating valve.

Hearing the click of a solenoid or using a screwdriver to check that the solenoid coil is energized does not ensure that the solenoid plunger has shifted. The following test will determine if the solenoid plunger is shifting.

The direction clutch pressure taps and the speed clutch pressure taps are installed in the transmission clutch solenoid modulating valves. The transmission clutch solenoid modulating valves are located on the top of the transmission beneath the cab.

Illustration 1	g00474494
Transmission Clutch Solenoid Modulating Valves (A) Number 1 clutch pressure tap. (B) Number 2 clutch pressure tap. (C) Number 3 clutch pressure tap. (D) Number 4 clutch pressure tap. (E) Number 5 clutch pressure tap. (F) Number 6 clutch pressure tap.

1. Install the correct hose assembly from 1U-5482 Pressure Adapter Group on pressure tap (A) through pressure tap (F). Attach the opposite end of the hose assembly to the 0 to 3400 kPa (0 to 580 psi) pressure gauge in the 1U-5481 Pressure Gauge Group .

2. Engage the parking brake. Shift the transmission direction and speed control lever (if equipped) to the NEUTRAL position. Shift the transmission direction control switch (if equipped) to the NEUTRAL position. Start the engine and operate the engine at low idle.

3. Place the transmission neutralizer override switch in the OFF position by depressing the top of the switch.

4. Depress the right service brake pedal and hold the right service brake pedal. Release the parking brake. Make sure that the machine is in first speed. Watch the pressure gauges. Move the transmission direction and speed control lever (if equipped) from the NEUTRAL position to the FORWARD position. Shift the transmission direction control switch (if equipped) from the NEUTRAL position to the FORWARD position.

   The needle on the pressure gauge for the Number 2 clutch should rise. The needle on the pressure gauge for the Number 6 clutch should rise. With the transmission in the FORWARD position, shift through the remaining forward speeds and return to the FIRST SPEED position. Use the transmission direction and speed control lever or the upshift switch to change speeds. The same pressure rise should be observed in each respective speed. This checks the operation of all the speed clutches.

5. Perform Step 4 for all reverse speeds. The same pressure rise should be noted in all reverse speeds.

If a pressure rise is noted, the solenoid and the related electrical circuit are functioning.

If a pressure rise is not noted, use a screwdriver to check that the solenoid coil is energized. If the screwdriver is attracted to the solenoid coil, this indicates that the solenoid coil is energized. The problem is in the solenoid cartridge. The problem could be a bent solenoid stem, a screen that is dirty or plugged, or a spring that is weak or broken.

If the screwdriver does not indicate that the solenoid coil is energized, the problem is in the electrical circuit.

Reference: For additional information about the transmission clutch solenoid modulating valves, refer to the Service Manual module Systems Operation, "Modulating Valves (Clutch Solenoid)" for the machine that is being serviced.

Reference: For additional information about calibrating the transmission clutch solenoid modulating valves, refer to the Service Manual module Testing and Adjusting, "Calibration" for the machine that is being serviced.

Reference: For additional information about electrical system troubleshooting, refer to the Service Manual module Testing and Adjusting, "Troubleshooting Service Codes" for the machine that is being serviced.

Transmission Clutch Pressure Test

Use the following procedure to check the pressure of the direction clutch oil and the speed clutch oil.

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Illustration 2	g00474494
Transmission Clutch Solenoid Modulating Valves (A) Number 1 clutch pressure tap. (B) Number 2 clutch pressure tap. (C) Number 3 clutch pressure tap. (D) Number 4 clutch pressure tap. (E) Number 5 clutch pressure tap. (F) Number 6 clutch pressure tap.

1. Install the correct hose assembly from the 1U-5482 Pressure Adapter Group on pressure tap (A) through pressure tap (F). Attach the opposite end of the hose assembly to the 0 to 3400 kPa (0 to 580 psi) pressure gauge in the 1U-5481 Pressure Gauge Group .

2. Engage the parking brake. Shift the transmission direction and speed control lever to the NEUTRAL position (if equipped). Shift the transmission direction control switch to the NEUTRAL position (if equipped). Start the engine and operate the engine at low idle.

3. Place the transmission neutralizer override switch in the OFF position by depressing the top of the switch.

4. Depress the right service brake pedal and hold the right service brake pedal. Release the parking brake. Make sure that the machine is in first speed. Watch the pressure gauges. Shift the transmission direction and speed control lever from the NEUTRAL position to the FORWARD position (if equipped). Shift the transmission direction control switch from the NEUTRAL position to the FORWARD position (if equipped). Increase the engine speed to high idle. Make sure that the transmission oil is at normal operating temperature. The needle on the pressure gauge for the Number 2 clutch should rise. The needle on the pressure gauge for the Number 6 clutch should rise. The pressure readings must be within the values in Table 3.

   With the transmission in the FORWARD position, shift through the remaining forward speeds and return to the FIRST SPEED position. Use the transmission direction and speed control lever (if equipped) or the upshift switch (if equipped) to change speeds. The pressure reading for each energized clutch must be within the values in Table 3. This checks the pressure of all the speed clutches.

5. Perform Step 4 for all reverse speeds. The same pressure levels should be noted in all reverse speeds.

Transmission Clutch Pressure Adjustment

If the pressure reading for each energized clutch is not within the values in Table 3, the transmission clutch solenoid modulating valve may need to be calibrated.

Reference: For more information, refer to the Transmission Clutch Engagement Calibration section in the Service Manual module Testing and Adjusting, "Calibration" for the machine that is being serviced.

Reference: For additional information about electrical system troubleshooting, refer to the Service Manual module Testing and Adjusting, "Troubleshooting Service Codes" for the machine that is being serviced.

Lubrication Oil Pressure Test

Use the following procedure to check the pressure of the transmission lubrication oil.

Illustration 3	g00297289
Inlet for Transmission Lubrication Oil (G) Transmission lubrication pressure tap.

The inlet for the transmission lubrication oil is located on the right side of the machine.

1. Install the correct hose assembly from the 1U-5482 Pressure Adapter Group on pressure tap (G). Attach the opposite end of the hose assembly to the 0 to 400 kPa (0 to 58 psi) pressure gauge in the 1U-5481 Pressure Gauge Group .

2. Start the engine and operate the engine at high idle. Observe the pressure gauge. With the oil at normal operating temperature, the lubrication oil pressure must be within the values in Table 3.

Torque Converter Outlet Pressure Test

Use the following procedure to check oil pressure at the torque converter outlet.

Illustration 4	g00297293
Torque Converter Outlet (H) Torque converter outlet pressure tap.

The torque converter outlet is located on the right side of the machine on the torque converter housing.

1. Install the correct hose assembly from the 1U-5482 Pressure Adapter Group on pressure tap (H). Attach the opposite end of the hose assembly to the 0 to 1000 kPa (0 to 145 psi) pressure gauge in the 1U-5481 Pressure Gauge Group .

2. Start the engine and operate the engine at high idle. Observe the pressure gauge. With the oil at normal operating temperature, the torque converter outlet pressure must be within the values in Table 3.

Transmission Oil Pump Pressure Test

Use the following procedure to check transmission oil pump pressure.

Illustration 5	g00297296
Transmission Oil Filter (J) Oil sampling valve for the transmission. (K) Pressure tap for the transmission oil pump.

The transmission oil filter is located above the parking brake on the left side of the machine.

Illustration 6	g00297297
Transmission Hydraulic Control Relief Valve (L) Pressure tap for the transmission oil pump. (M) Pressure tap for P3 torque converter inlet oil pressure.

The transmission hydraulic control relief valve is located on the left side of the machine on the torque converter housing.

1. Install the correct hose assembly from the 1U-5482 Pressure Adapter Group on pressure tap (K). Attach the opposite end of the hose assembly to the 0 to 3400 kPa (0 to 580 psi) pressure gauge in the 1U-5481 Pressure Gauge Group .

2. Install the correct hose assembly from the 1U-5482 Pressure Adapter Group on pressure tap (L). Attach the opposite end of the hose assembly to the 0 to 3400 kPa (0 to 580 psi) pressure gauge in the 1U-5481 Pressure Gauge Group .

3. Start the engine and operate the engine at high idle. Observe the pressure gauges. With the oil at normal operating temperature, the transmission oil pump pressure must be within the values in Table 3.

Transmission Oil Pump Pressure Adjustment

Illustration 7	g00297297
Transmission Hydraulic Control Relief Valve (L) Pressure tap for the transmission oil pump. (M) Pressure tap for P3 torque converter inlet oil pressure.

The transmission hydraulic control relief valve is located on the left side of the machine on the torque converter housing.

Illustration 8	g00312809
Transmission Hydraulic Control Relief Valve (N) Cover.

Illustration 9	g00312810
Transmission Hydraulic Control Relief Valve (P) Adjustment screw.

If the transmission oil pump pressure at pressure tap (L) is not within the values in Table 3, adjust the spring of the transmission hydraulic control relief valve. Use the following procedure.

1. Remove cover (N) .

2. Turn adjustment screw (P) in the proper direction.

   Turning the adjustment screw clockwise increases pump pressure. Turning the adjustment screw counterclockwise decreases pump pressure. One full turn of the adjustment screw changes pump pressure 160 kPa (23 psi).

3. Install cover (N) .

4. Check the transmission oil pump pressure again. Make sure that the transmission oil pump pressure is within the value in Table 3.

Torque Converter Inlet Pressure Test

Illustration 10	g00297297
Transmission Hydraulic Control Relief Valve (L) Pressure tap for the transmission oil pump. (M) Pressure tap for P3 torque converter inlet oil pressure.

The transmission hydraulic control relief valve is located on the left side of the machine on the torque converter housing.

1. Install the correct hose assembly from the 1U-5482 Pressure Adapter Group on pressure tap (M). Attach the opposite end of the hose assembly to the 0 to 2000 kPa (0 to 290 psi) pressure gauge in the 1U-5481 Pressure Gauge Group .

2. Start the engine and operate the engine at high idle. Observe the pressure gauge. With the oil at normal operating temperature, the torque converter inlet pressure must be within the values in Table 3.

Transmission Pressures